Numerical Simulation of Frictional Heating Effects of Sliding Friction Bearings for Isolated Bridges

Sliding friction bearings are effective passive devices to mitigate the seismic responses of structures. Extensive researches have been conducted on sliding bearings. However, most previous studies were based on the assumption that the effects of frictional heating are negligible. A three-dimensional thermal-mechanical-coupled finite element (FE) model of the friction pendulum system (FPS) was developed in this study. Good agreements between the numerical results and the data measured in the previous tests, in terms of the force–displacement curves and temperature time-histories, indicate that the proposed FE model can predict the response of the FPS. Based on the developed FE model, the surface temperature distribution, the effective stiffness and the energy dissipation of the double concave friction pendulum and multiple friction pendulum bearings were investigated and compared. In addition, the thermal states of the sliding bearings in the bridge during earthquake were evaluated. The numerical results indicate that the temperature rise in the sliding bearings leads to the degradation of the effective stiffness and less energy dissipation. The relative displacements of the bearings increase considering the frictional heating effects in the bearings. If the frictional heating of the bearings is ignored, the peak bearing displacements will be underestimated.